Abstract
The contamination of coliform groups were investigated on 1,969 and 220 samples of individual well water in Tokyo from May to December in 1991 and from May to November in 1992, respectively. Coliform groups were isolated in 672 from 1,969 samples (34.1%) in 1991 and in 85 from 220 samples (38.6%) in 1992.
The numbers of coliform groups were detected from 1-2,000 CFU per 100ml of individual well water samples.
One hundred thirteen strains isolated were identificated in Enterobacter (27.5%), Klebsiella (26.6%), Serratia (15.0%), Citrobacter (8.9%), Kluyvera (6.1%), Escherichia (4.4%), Rahnella (3.5%), Leclercia (0.9%) and Unknown (7.1%).
The most predominant species of coliform groups in individual well water samples were K. pneumoniae (14.2%), which were followed by E. cloacae (11.5%) and K. oxytoca (10.6%)
5 strains of E. coli was isolated from 113 strains (4.4%).
